Ultrasound Emitter (MSB122E)

The circuit shown by the figure below can produce signals in the range between 20 kHz and 30 kHz. Power supply can range from 6 to 9 V… If you replace Q2 at a BD136, power voltage can be increased to 12 V. R2 adjusts the frequency; The wave shap displayed by the oscilloscope doesn’t correspond to the real due the algorithm in the MultiSIM. This displays only is used to see that the circuit oscillates.